FR2974165A1 - THERMAL INSTALLATION FOR SHOPPING CENTER. - Google Patents

Abstract

A shopping center heat installation comprises a first refrigeration unit (10) connected to a food cold circuit (4), and a second refrigeration unit (30) connected to an air conditioning circuit (6), said air conditioning circuit (6). comprising a cold storage device (56). It also comprises two links between the food cold circuit (4) and the air conditioning circuit (6), each link being controlled by a control valve (58, 60).

Description

LARQUETOUMALDONADO 1.FRD

Thermal installation for shopping center

The invention relates to a thermal installation for buildings of the shopping center type. Such a thermal installation includes the production of food cold and air conditioning. In certain embodiments, it also includes heating by direct production and / or recovery, and is coupled where appropriate to a cogeneration energy production system.

Shopping centers are buildings whose energy needs are very important. Indeed, they shelter surfaces intended to shelter perishable food products, which requires a control of the cold chain. In addition to the sales area is usually a commercial gallery, offices and warehouses. At the same time, it is necessary to adjust the thermal comfort in the building according to the rate of use, the use of equipment and the outside temperature.

Currently, the thermal installations of this type of building are built independently of each other. This leads to increased electricity consumption, soaring operating costs, and even an inability to meet the needs and difficulties related to the regulation of various systems and the maintenance of equipment. In the modern context of hunting energy losses, and given the rising cost of energy, particularly electric energy, this situation is particularly unsatisfactory.

The invention improves the situation.

For this purpose, the invention proposes a thermal installation for a shopping center, comprising a first refrigeration unit connected to a food cold circuit, and a second refrigeration unit connected to an air conditioning circuit, said air conditioning circuit comprising a storage device. cold. This installation also comprises two connections between the food cold circuit and the air conditioning circuit, each connection being controlled by a control valve. Other characteristics and advantages of the invention will appear better on reading the description which follows. FIG. 1 represents a first embodiment of a thermal installation according to the invention, FIGS. FIG. 8 shows a second embodiment of a thermal installation according to the invention, and FIG. 9 represents a third embodiment of a thermal installation according to the invention.

The drawings and the description below contain, for the most part, elements of a certain character. They can therefore not only serve to better understand the present invention, but also contribute to its definition, if any.

Modern shopping centers are places where a lot of energy is consumed, both for lighting and for the production of cold and heat. The peculiarity of commercial buildings lies in the fact that these buildings need both hot and cold at the same time.

The same can be said for hypermarkets alone, or for shopping centers without hypermarkets. The term shopping center therefore aims at both a shopping center including or not a hypermarket, and a hypermarket alone.

The thermal installations of the companies cohabiting in this type of buildings are traditionally separated. This is because the technical batches for refrigeration, heating and cooling are separate.

In addition, although the trades are similar, the skills required differ. As a result, the personnel of the technical batches for refrigeration, heating and air conditioning do not always intervene at the same time during construction. For example, the refrigeration lot usually comes last. 20 This design, although relatively inefficient, has not been a major problem to date, as the high-energy shopping centers were located in mature countries where energy is cost-effective, and the grid energy is reliable.

With globalization, shopping centers have been developed in all countries of the world. These shopping centers are now challenging, either to power them electrically with reasonable cost, or to avoid overloading the energy grid and / or prevent failures of this grid.

In addition, local technical knowledge for some technical batches may be missing after installation. Maintenance costs can then fly off, dangerously impacting the daily profit of the shopping center. Currently, the important thing is to guarantee an energy performance of the shopping center through a centralized technical management of the different technical batches.

FIG. 1 represents a first embodiment of a thermal installation for a shopping center according to the invention.

The thermal installation 2 comprises a food cold circuit 4 and an air conditioning circuit 6. The food cold circuit 4 is mainly dedicated to the management of the temperature of the refrigerant fluid in the showcases, gondolas and other cold rooms, while the Air conditioning circuit 6 is dedicated to the management of air conditioning in the mall.

The food cold circuit 4 comprises a first refrigerating unit 10, a stop valve 12, a pump 16, showcases, gondolas and cold rooms 18, an expansion tank 20, a pressure drop valve 22, and a pump 24.

The first cooling unit 10 cools the refrigerant fluid to supply the evaporator circuit in a branch called "distribution branch", which comprises the motorized shut-off valve 12. Once it has passed through the distribution branch, the coolant fluid is slightly warmed because it gave up cold during its crossing, and it has a temperature of about 5 ° C more than at its outlet of the first refrigerating unit 10.

The refrigerant fluid then returns to the first refrigerating unit 10 through a so-called "return branch" branch, which comprises the pump 24. It is the pump 24 which reinjects the refrigerant fluid of the return branch into the refrigeration unit 10 to start again. the loop.

In the example described here, the shutoff valve 12 is motorized, and serves to stop the first refrigeration unit 10. Downstream of the stop valve 12, the distribution branch comprises the pump 16. In the example described here, the pump 16 is adjustable in frequency, depending on the pressure. This adjustment depends on the measurements taken from the membrane pressure drop valve 22, which is arranged upstream of the pump 16 between the distribution branch and the return branch. The distribution branch ends with the connection between the pump 16 and the showcases, gondolas and cold rooms 18 for their supply of coolant fluid.

The return branch starts downstream of the showcases, gondolas and cold rooms 18, and extends to the expansion tank 20, upstream of which is connected the pressure drop valve 22, and ends with the pump 24.

The air-conditioning circuit 6 comprises a second refrigeration unit 30, a shut-off valve 32, a cold storage circuit 34, an adjustment valve 36, a pump 38, a sensor 40, an exchanger 42, a storage vessel expansion 44, a shutoff valve 46, a shutoff valve 48, and a pump 50. The cold storage circuit 34 includes a shutoff valve 52, a sensor 54, and a cold storage device 56.

The second refrigerating unit 30 receives the slightly heated secondary refrigerant fluid from the pump 50 in a branch referred to as a "return branch" of the evaporator circuit of the second refrigeration unit 30, and cools it to reintroduce it into a branch qualified as a "distribution branch". of the evaporator circuit of the second refrigerating unit 30, and which comprises the valve 32.

In the example described here, the stop valve 32 is motorized, and is used to stop the second refrigeration unit 30. Downstream of the stop valve 32, the distribution branch comprises the cold storage circuit 34, whose admission is adjusted by the stop valve 52. In the example described here, the stop valve 52 is motorized. The operation of the cold storage circuit 34 will be described below.

Downstream of the cold storage circuit 34, the distribution branch is connected to the inlet of the control valve 36. In the example described here, the control valve 36 is a motorized three-way valve with two inputs and one exit. The output path is connected to the pump 38. The pump 38 is motorized and supplies the exchanger 42 through the sensor 40. An input path is connected downstream of the cold storage circuit 34, and the other path the inlet of the control valve 36 is connected to the return branch, and thus constitutes a fluid reintroduction means in the exchanger 42.

In the example described here, the exchanger 42 serves to cool the liquid of the air conditioning system 10 of the mall. The sensor 40 measures the cooling requirements of the air conditioning system and makes it possible to control the valve 36 accordingly.

The return branch begins downstream of the exchanger 42. It joins the reintroduction branch, as well as an input / output branch of the cold storage circuit 34. Still downstream, the return branch comprises the vessel of expansion 44 and the stop valve 46, which is in the example described here motorized. The stop valve 46 is itself connected to the inlet of the pump 50 which supplies the second cooling unit 30 with heated fluid.

The plant 2 also comprises a valve 58 and a valve 60. The valve 58 connects the return branch of the evaporator circuit of the first refrigeration unit 10 and the return evaporator return branch of the evaporator circuit of the second refrigeration unit 30, and is arranged between the pump 24 on the one hand and the pump 50 on the other hand.

The valve 60 connects the distribution branch of the evaporator circuit of the first refrigeration unit 10 and the distribution branch of the evaporator circuit of the second refrigeration unit 30, and is arranged between the pump 16 on the one hand, and the stop valve 32 on the other hand.

The stop valve 48 is connected downstream to the stop valve 46, and a non-return valve not shown is arranged downstream between the stop valve 60, between the latter and the stop valve 48, and circulates the fluid from the dispensing branch to the return branch of the evaporator circuit of the second refrigeration unit 30. In the example described herein, the valve 58 and the valve 60 are dispensing and stopping valves which allow selectively connect, or "merge" the food cold circuit 4 and the air conditioning circuit 6. The description of Figures 2 to 7 will better understand the interest of these valves. On the left of Figure 2, a circuit 62 said condenser for cooling the evaporator circuit of the first refrigerating unit 10 and the second group 30 is shown.

The condenser circuit 62 comprises a valve 64, a valve 66, a valve 68, a valve 70, an air cooler 72, an expansion vessel 74 and a pump 76. The outputs of the valves 64 and 66 are interconnected by a branch in which the circulation of the refrigerant fluid of the condenser circuit 62 is from the valve 64 to the valve 66.

The valve 64 is connected to the second refrigerating unit 30, and is in the example described a motorized shut-off valve of the condenser circuit of the second refrigerating unit 30. The valve 66 is connected to the first refrigerating unit 10, and is in the example describes a motorized shut-off valve of the condenser circuit of the first refrigerating unit 10.

Downstream of the valve 66, the valve 68 on the one hand, and the valve 70 and the air cooler 72 on the other hand are arranged in parallel. In the example described here, the valve 68 is a motorized control valve of the drycooler 72, and the valve 70 is a motorized shutoff valve. The valve 68 and the valve 70 cooperate together to control the amount of refrigerant fluid from the first refrigeration unit 10 and the second refrigeration unit 30 which passes through the air cooler 72. The operation of the valves 68 and 70 will be described below. The air cooler 72 has the function of cooling the refrigerant fluid therethrough. Indeed, to produce cold in the evaporator circuits of the first refrigerating unit 10 and the second refrigerating unit 30, it is necessary to remove the accumulated calories in the distribution branches. Downstream of the valves 68 and 70, the condenser circuit 62 comprises an expansion vessel 74, which is connected to a pump 76. In the example described here, the pump 76 may comprise two operating pumps and a redundancy pump, in case of failure. The pump 76 supplies firstly the first refrigerating unit 10 and secondly the second refrigerating unit 30 for cooling the fluid of their respective evaporator circuits.

FIGS. 2 to 7 represent the various operating modes of the installation 2. On each of these diagrams, the circuit followed by the cold-carrying fluid in the evaporator circuits is represented by a thick line, as opposed to the fine lines, which represent the parts of the evaporator circuits in which the fluid does not circulate. Arrows indicate the flow direction of the fluid.

In FIG. 2, an operating mode is shown in which the food cold circuit 4 and the air conditioning circuit 6 operate independently, in the night mode.

At night, the cooling needs of showcases, gondolas and cold rooms 18 are of the order of 30% to 40% of daily needs. In this case, the first refrigeration unit 10 is activated, the shut-off valve 12 is open, and the pumps 16 and 24 operate. As the food cold circuit 4 and the air conditioning circuit 6 are separated, the stop valves 58 and 60 are closed.

At night, there is no need for air conditioning, and exchanger 42 does not work. The control valve 12 is closed, and the pump 38 is stopped. All the coolant fluid is directed to the shutoff valve 52 of the cold storage circuit 34, which is open. In this operating mode, the temperature setpoint at the outlet of the second refrigeration unit 30 is -7.8 ° C. The second refrigeration unit 30 then operates at full load to charge the cold storage device 56 cold, and the refrigerant fluid at the outlet of the latter reaches the return branch of the evaporator circuit of the second refrigeration unit 30 towards the vessel. Expansion 44. For this, the pump 50 is activated, the stop valve 32 and the stop valve 46 are open, and the stop valve 48 is closed. The condenser circuit 62 discharges the rejected calories generated by the cold production to the evaporator circuit of the first refrigeration unit 10 and the second refrigeration unit 30.

For this, when the fluid temperature of the condenser circuit 62 reaches 40 ° C, at plus or minus 2 ° C, the control valve 68 is closed, while the stop valve 70 is open. Otherwise, the valve 68 is open, and the stop valve 70 is closed.

When the valve 68 is closed and the valve 70 open, the fluid passes through the air cooler 72, whose fans will activate, to cool the coolant through the outside air. The valve 68 is controlled in opening and closing to ensure that the fluid of the condenser circuit 62 remains above 25 ° C. The air cooler 72 thus functions as a "valve" for evacuating too many calories.

The operating mode of FIG. 2 represents a cycle start mode. At startup, the temperature of the refrigerant fluid is greater in the air conditioning circuit 6, in which it is of the order of 8 ° C, than in the food cold circuit 4, in which it is of the order of - 2 ° C.

As the two circuits operate separately, the temperature of the refrigerant fluid in the air conditioning circuit 6 is gradually lowered, while that of the refrigerant fluid in the food cold circuit 4 remains stable. Once the temperature of the refrigerant fluid in the air conditioning circuit 6 approaches -2 ° C, the food cold circuit 4 and the air conditioning circuit 6 are ready to be fused.

FIG. 3 represents a mode of operation in which the food cold circuit 4 and the air conditioning circuit 6 have merged.

Indeed, we have seen with the description of Figure 2 that at night, the first refrigerating unit 10 needs to operate at a level between 30% and 40% of its capacity. It is therefore advantageous to open the valves 58 and 60 in order to use the remaining power of the first refrigeration unit 10 for the cold storage device 56.

During the beginning of the cycle, the temperature in the evaporator circuit of the refrigerating unit 30 was gradually brought to -2 ° C. This temperature corresponds to that of the refrigerant fluid of the food cold circuit 4.

When this temperature setpoint is reached, the valves 58 and 60 open. The first refrigerating unit 10 and the second cooling unit 30 then work together to charge the cold storage device 56. The food cold circuit 4 and the air conditioning circuit 6 have then merged.

This arrangement makes it possible, at constant electric power, to charge the cold storage device 56 more rapidly. Thus, depending on the needs of the building, it may be advantageous to oversize the storage device 34 by approximately 50-60%, which corresponds to the addition of the first refrigerating unit 10.

This over-sizing allows in return to meet all the needs for air conditioning during the day, without practically soliciting the second refrigerating unit 30. Another advantage is that, as the first refrigerating unit 10 and the second refrigerating unit 30 operate at full load, it becomes possible to recover the maximum of calories in the condenser circuit 2, as will be explained with FIG. 8.

When the return temperature in the return branch of the second refrigeration unit 30 reaches the temperature of -5 ° C, the cold storage device 56 is charged, and the second refrigeration unit 30 is stopped. The food cold circuit 4 and the air conditioning circuit 6 are then separated again, by closing the valves 58 and 60.

This operating mode is illustrated in FIG. 4. The pump 16 of the food cold circuit 4 then operates at a level comprised between 30% and 40% of its normal capacity for cooling the showcases, gondolas and cold rooms 18, while the air conditioning circuit 6 is closed. For this, the stop valves 32 and 52 are closed, and the pump 50 is stopped.

FIG. 5 represents the mode of operation following in time the operating mode of FIG. 4.

The operating mode of FIG. 5 corresponds to the use of the thermal installation 2 at the beginning of the day. During the morning, the air conditioning needs are not maximum, and it is not necessarily useful to start emptying the cold storage device 56. The food cold circuit 4 then operates similar to what has been presented. with Figures 2 to 4, with a suitable adjustment of the flow rate of the pump 16 according to the cold requirements for showcases, gondolas and cold rooms 18.

The air conditioning circuit 6 then operates in a conventional manner, that is to say without using the cold storage circuit 34. In this operating mode, the pumps 38 and 50 are activated, the shut-off valves 32 , 46 and 48 are open, the shut-off valve 10 is closed, and the regulating valve 12 makes it possible to regulate the temperature of the fluid at the inlet of the exchanger 42. In the example described here, the second cooling unit 30 and the valve 36 are used to obtain a temperature of 4 ° C. at the inlet of the exchanger 42.

As the day progresses, the temperature rises, and the attendance at the mall also.

20 The needs for air conditioning are gradually increasing, and the choice of the most appropriate strategy for the production of cooling according to the electric tariff and the maximum available power will be required: - either the system of regulation of the needs in air conditioning determines that the cold storage device 56 will not be sufficient to meet all the needs of the day, and the installation 2 is arranged according to the operating mode of FIG. 6, or the air conditioning control system determines that the cold storage device 56 will be sufficient to satisfy all the needs of the day, and the installation 2 is arranged according to the operating mode of FIG. 7.

In the operating mode shown in FIG. 6, the valve 48 is closed, in order to properly separate the distribution branch and the return branch, while the cold storage device 56 is activated. Thus, at the outlet of the exchanger 42, the fluid of the return branch passes partly into the cold storage device 56 in which it is cooled, and mixed by the control valve 36 to maintain the set point of 4 ° C. at the inlet of the exchanger 42.5 The operation of the food cold circuit 4 is unchanged, and the pump 16 generally operates at a level between 60% and 70% of its capacity.

In the operating mode shown in FIG. 7, the second refrigerating unit 30 and the pump 50 are stopped, and the shut-off valves 32, 46, 48 and 54 are closed. The cold storage device 56 is activated and the control valve 36 provides the temperature setpoint at the inlet of the exchanger 42.

The operation of the food cold circuit 4 is unchanged, and the pump 16 generally operates at a level which depends on the need for cold food.

This mode of operation is particularly advantageous because it makes it possible to smooth the consumption of electricity when the peak of consumption is reached. This both reduces the electricity bill consumed, but also reduces the risk of overloading the grid to which the shopping center is connected. This mode of operation is all the more advantageous as the melting of the food cold circuit 4 and the air conditioning circuit 6 makes it possible to use an oversized cold storage device 56.

The operating mode of FIG. 7 can also be activated at any time, for example when there is a peak power consumption or a risk of saturation of the available electrical power required by various needs, including by air conditioning. The second cooling unit 30 is then stopped, and the cold storage device 56 takes the relay, cooling the fluid before the entry of the exchanger 42.

In addition to the operating modes described in FIGS. 2 to 7, the installation 2 has the advantage of offering a redundant nature in the event of failure of the first refrigeration unit 4 or the second refrigeration unit 30.

Indeed, in a conventional installation, since the circuits are independent of each other, the possible redundancy equipment must be provided with each circuit. This is expensive and inefficient.

The thermal installation 2 allows, by the valves 58 and 60, to offer a solution to this problem, since it is possible to merge the food cold circuit 4 and the air conditioning circuit 6 if a failure is detected on the first refrigerating unit 10 or the second cooling unit 30. In the example described here, the refrigerating units 10 and 30 have a near cold power, and each have at least two compressors with independent circuits.

In this case, it is the maintenance of the temperature in the windows, gondolas and cold rooms 18 which is a priority, that is to say that the pumps 38 and 50 of the air conditioning circuit 6 will be controlled with a level dictated by the needs of the pumps 16 and 24 of the food cold circuit 4.

In this case, the use of the cold storage device 56 will likely be necessary to meet the needs of the exchanger 42 for the air conditioning circuit.

In addition, whenever either of the first refrigeration unit 10 and the second refrigeration unit 30 is activated, the condenser circuit 62 is activated to cool their fluid. Although the condenser circuit 62 has advantageously been shown here as common to the first refrigerating unit 10 and the second refrigerating unit 30, it would be possible to provide a condenser circuit 62 for each of them.

Figure 8 shows a second embodiment in which the thermal plant 2, which includes a heat recovery system.

Figure 8 has been simplified, and refers only to the new elements of the installation 2 and the elements thereof to which these elements are connected. As can be seen in this figure, the recovery elements are connected to the condenser circuit 62, by a branch called "distribution branch" which comes to collect the heated fluid of the condenser circuit 62 at the output of the connection between the valves 64 and 66, and by a branch called "return branch", which reintroduces the cooled fluid after heat recovery downstream of the valves 68 and 70 to the expansion vessel 72.

Depending on the needs of the building and the outside temperature, for example depending on whether it is summer or winter, the heat recovery at the condenser circuit 62 may be partial or total. The maximum calorie recovery is obtained by opening the valve 68, by closing the valve 70.

In the case of total recovery, the heat output recovered is equal to the cold power added of the compressor power of the first refrigerating unit 10 and the second cooling unit 30. This represents a recovery of about 130% of the cold power. . In winter, this should cover most heat requirements in many countries.

The distribution branch splits into two sub-branches each comprising a stop valve referenced 78 and 80 respectively. In the example described here, the stop valves 78 and 80 are motorized shut-off valves.

The sub-branch which includes the stop valve 78 is directed to an air treatment component 82. The component 82 is arranged to recover calories from the fluid of this branch to produce hot air, and which returns the cooled fluid in the return branch.

The sub-branch which includes the shut-off valve 80 is directed to a sanitary water circuit 84. The sanitary water circuit 84 comprises a heat exchanger (not shown) which is arranged to recover calories from the fluid of this branch to produce hot water, which returns the cooled fluid to the return branch.

In general, the operating modes of the installation 2 described with reference to FIGS. 2 to 7 do not change with the installation of FIG. 8. The only change lies in the activation of the condenser circuit 2, in wherein the calories of the evaporator circuits are first removed by means of the component 82 and the circuit 84, and wherein the valves 68 and 70 and the air cooler are then controlled only to evacuate excess calories not used by the component 82 and the circuit 84.

FIG. 9 represents a third embodiment allowing the realization of an even more advantageous thermal installation 2. In this embodiment, not only does the thermal installation comprise the heat recovery elements of FIG. 8, but it also comprises redundant elements, both functional and structural.

Thus, each of the pumps 16, 24, 38, 50 and 76 is doubled, by means of a pump which is arranged in parallel, in addition to the possible reserve pump already present for the pump 76.

In addition to this, the plant 2 comprises two gas generators 90 and 92 for a cogeneration operation. The heat produced by the generators is then transferred for the building heating and domestic hot water production. For this, the generators 90 and 92 are connected to exchangers 94 and 96.

The exchanger 94 uses the heat produced by the generating sets 90 and 92 to transmit it to the component 82. The exchanger 96 uses the heat generated by the generating sets 90 and 92 to transmit it to the circuit 84. An adjustment valve 98 allows to control the exchanger 94 and a control valve 100 makes it possible to control the heat exchanger 96. An air-cooler 102 is also provided for evacuating the calories that are not used in the exchangers 94 and 96. The air-dryer is controlled by a valve 104 for the case where the heating demand is low. The excess heat is then evacuated by the air cooler 102.

This installation is therefore both totally reliable and energy efficient.20

Claims (6)

REVENDICATIONS1. Thermal plant for a shopping center, comprising a first refrigeration unit (10) connected to a food cold circuit (4), and a second refrigerating unit (30) connected to an air conditioning circuit (6), said air conditioning circuit (6) comprising a cold storage device (56), characterized in that it also comprises two connections between the food cold circuit (4) and the air conditioning circuit (6), each connection being controlled by a control valve (58). , 60). 10 2. The mall heat plant of claim 1, further comprising a condenser circuit (62) arranged to cool the fluid of the first refrigeration unit (10) and the second refrigeration unit (30). 3. Thermal plant according to claim 2, further comprising a heat recovery circuit connected to the condenser circuit. 4. Thermal plant according to claim 3, further comprising gas generating sets (90, 92) connected to the heat recovery circuit. 20 5. Thermal plant according to one of the preceding claims, comprising in each circuit at least one pump, and a stop valve. 6. Thermal plant according to one of the preceding claims, further comprising a control valve located between the cold storage device (56), a distribution branch of the air conditioning circuit (6), and a return branch of the air conditioning circuit (6).